Re you looking for a shooter or a collector?
If shooter I would get one of the Israeli surplus .308 weapons. (7.62 NATO much easier to come by and cheaper to shoot than 8mm Mauser)
If it is for a collecter, get one with the waffen stamp on it or a DWM. One made in a German factory.
Try to find matching bolt serial #'s and if it is not 8mm then it has been reworked.
Orso